Electronic circuit assemblies customarily employed for implementing telecommunication systems may comprise one or more printed wiring boards, upon which circuit components are mounted and interconnected, and an underlying electrically and thermally conductive support member, such as an aluminum plate, which serves as both a heat sink and a printed wiring board stiffener. Attachment of a printed wiring board to such a metallic plate is customarily accomplished by means of an adhesive that is both thermally conductive (for providing a heat removal path from the circuit components to the heat sink plate) and is an effective dielectric (for ensuring electrical isolation between the printed wiring board and the aluminum plate and preventing unwanted shorting of the circuit components).
Unfortunately, conventional adhesives that satisfy both of these requirements require an elevated curing temperature (on the order of 250 to 400 degrees F.). Because of the substantial mismatch between the respective coefficients of thermal expansion of the printed wiring board material and the aluminum stiffener, the intended (usually planar) configuration of the printed wiring board, aluminum stiffener laminate structure becomes distorted (warped) upon returning to room temperature. In addition, regardless of whatever cure temperature is required, it is absolutely essential that there be no flow of the adhesive into critical regions of the printed wiring board.